using System;
using System.Linq;

public class Test
{
	public static void Main()
	{
		Console.ReadLine();
		var x = Console.ReadLine().Split(' ')
			.Select(n => int.Parse(n)).ToArray();
		
		Array.Sort(x);
		
		var ans = 1000001;
		for(int i = 1; i < x.Length; ++i)
		{
			if(x[i] == x[i - 1]) continue;
			ans = (ans < x[i] - x[i - 1]) ? ans : x[i] - x[i - 1];
		}
		
		if(ans == 1000001) ans = 0;
		Console.WriteLine(ans);
	}
}